hdc2010.c

  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * hdc2010.c - Support for the TI HDC2010 and HDC2080
  4 * temperature + relative humidity sensors
  5 *
  6 * Copyright (C) 2020 Norphonic AS
  7 * Author: Eugene Zaikonnikov <ez@norphonic.com>
  8 *
  9 * Datasheet: https://www.ti.com/product/HDC2010/datasheet
 10 * Datasheet: https://www.ti.com/product/HDC2080/datasheet
 11 */
 12
 13#include <linux/module.h>
 14#include <linux/init.h>
 15#include <linux/i2c.h>
 16#include <linux/bitops.h>
 17
 18#include <linux/iio/iio.h>
 19#include <linux/iio/sysfs.h>
 20
 21#define HDC2010_REG_TEMP_LOW			0x00
 22#define HDC2010_REG_TEMP_HIGH			0x01
 23#define HDC2010_REG_HUMIDITY_LOW		0x02
 24#define HDC2010_REG_HUMIDITY_HIGH		0x03
 25#define HDC2010_REG_INTERRUPT_DRDY		0x04
 26#define HDC2010_REG_TEMP_MAX			0x05
 27#define HDC2010_REG_HUMIDITY_MAX		0x06
 28#define HDC2010_REG_INTERRUPT_EN		0x07
 29#define HDC2010_REG_TEMP_OFFSET_ADJ		0x08
 30#define HDC2010_REG_HUMIDITY_OFFSET_ADJ		0x09
 31#define HDC2010_REG_TEMP_THR_L			0x0a
 32#define HDC2010_REG_TEMP_THR_H			0x0b
 33#define HDC2010_REG_RH_THR_L			0x0c
 34#define HDC2010_REG_RH_THR_H			0x0d
 35#define HDC2010_REG_RESET_DRDY_INT_CONF		0x0e
 36#define HDC2010_REG_MEASUREMENT_CONF		0x0f
 37
 38#define HDC2010_MEAS_CONF			GENMASK(2, 1)
 39#define HDC2010_MEAS_TRIG			BIT(0)
 40#define HDC2010_HEATER_EN			BIT(3)
 41#define HDC2010_AMM				GENMASK(6, 4)
 42
 43struct hdc2010_data {
 44	struct i2c_client *client;
 45	struct mutex lock;
 46	u8 measurement_config;
 47	u8 interrupt_config;
 48	u8 drdy_config;
 49};
 50
 51enum hdc2010_addr_groups {
 52	HDC2010_GROUP_TEMP = 0,
 53	HDC2010_GROUP_HUMIDITY,
 54};
 55
 56struct hdc2010_reg_record {
 57	unsigned long primary;
 58	unsigned long peak;
 59};
 60
 61static const struct hdc2010_reg_record hdc2010_reg_translation[] = {
 62	[HDC2010_GROUP_TEMP] = {
 63		.primary = HDC2010_REG_TEMP_LOW,
 64		.peak = HDC2010_REG_TEMP_MAX,
 65	},
 66	[HDC2010_GROUP_HUMIDITY] = {
 67		.primary = HDC2010_REG_HUMIDITY_LOW,
 68		.peak = HDC2010_REG_HUMIDITY_MAX,
 69	},
 70};
 71
 72static IIO_CONST_ATTR(out_current_heater_raw_available, "0 1");
 73
 74static struct attribute *hdc2010_attributes[] = {
 75	&iio_const_attr_out_current_heater_raw_available.dev_attr.attr,
 76	NULL
 77};
 78
 79static const struct attribute_group hdc2010_attribute_group = {
 80	.attrs = hdc2010_attributes,
 81};
 82
 83static const struct iio_chan_spec hdc2010_channels[] = {
 84	{
 85		.type = IIO_TEMP,
 86		.address = HDC2010_GROUP_TEMP,
 87		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 88			BIT(IIO_CHAN_INFO_PEAK) |
 89			BIT(IIO_CHAN_INFO_OFFSET) |
 90			BIT(IIO_CHAN_INFO_SCALE),
 91	},
 92	{
 93		.type = IIO_HUMIDITYRELATIVE,
 94		.address = HDC2010_GROUP_HUMIDITY,
 95		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 96			BIT(IIO_CHAN_INFO_PEAK) |
 97			BIT(IIO_CHAN_INFO_SCALE),
 98	},
 99	{
100		.type = IIO_CURRENT,
101		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
102		.extend_name = "heater",
103		.output = 1,
104	},
105};
106
107static int hdc2010_update_drdy_config(struct hdc2010_data *data,
108					     char mask, char val)
109{
110	u8 tmp = (~mask & data->drdy_config) | val;
111	int ret;
112
113	ret = i2c_smbus_write_byte_data(data->client,
114					HDC2010_REG_RESET_DRDY_INT_CONF, tmp);
115	if (ret)
116		return ret;
117
118	data->drdy_config = tmp;
119
120	return 0;
121}
122
123static int hdc2010_get_prim_measurement_word(struct hdc2010_data *data,
124					     struct iio_chan_spec const *chan)
125{
126	struct i2c_client *client = data->client;
127	s32 ret;
128
129	ret = i2c_smbus_read_word_data(client,
130			hdc2010_reg_translation[chan->address].primary);
131
132	if (ret < 0)
133		dev_err(&client->dev, "Could not read sensor measurement word\n");
134
135	return ret;
136}
137
138static int hdc2010_get_peak_measurement_byte(struct hdc2010_data *data,
139					     struct iio_chan_spec const *chan)
140{
141	struct i2c_client *client = data->client;
142	s32 ret;
143
144	ret = i2c_smbus_read_byte_data(client,
145			hdc2010_reg_translation[chan->address].peak);
146
147	if (ret < 0)
148		dev_err(&client->dev, "Could not read sensor measurement byte\n");
149
150	return ret;
151}
152
153static int hdc2010_get_heater_status(struct hdc2010_data *data)
154{
155	return !!(data->drdy_config & HDC2010_HEATER_EN);
156}
157
158static int hdc2010_read_raw(struct iio_dev *indio_dev,
159			    struct iio_chan_spec const *chan, int *val,
160			    int *val2, long mask)
161{
162	struct hdc2010_data *data = iio_priv(indio_dev);
163
164	switch (mask) {
165	case IIO_CHAN_INFO_RAW: {
166		int ret;
167
168		if (chan->type == IIO_CURRENT) {
169			*val = hdc2010_get_heater_status(data);
170			return IIO_VAL_INT;
171		}
172		if (!iio_device_claim_direct(indio_dev))
173			return -EBUSY;
174		mutex_lock(&data->lock);
175		ret = hdc2010_get_prim_measurement_word(data, chan);
176		mutex_unlock(&data->lock);
177		iio_device_release_direct(indio_dev);
178		if (ret < 0)
179			return ret;
180		*val = ret;
181		return IIO_VAL_INT;
182	}
183	case IIO_CHAN_INFO_PEAK: {
184		int ret;
185
186		if (!iio_device_claim_direct(indio_dev))
187			return -EBUSY;
188		mutex_lock(&data->lock);
189		ret = hdc2010_get_peak_measurement_byte(data, chan);
190		mutex_unlock(&data->lock);
191		iio_device_release_direct(indio_dev);
192		if (ret < 0)
193			return ret;
194		/* Scaling up the value so we can use same offset as RAW */
195		*val = ret * 256;
196		return IIO_VAL_INT;
197	}
198	case IIO_CHAN_INFO_SCALE:
199		*val2 = 65536;
200		if (chan->type == IIO_TEMP)
201			*val = 165000;
202		else
203			*val = 100000;
204		return IIO_VAL_FRACTIONAL;
205	case IIO_CHAN_INFO_OFFSET:
206		*val = -15887;
207		*val2 = 515151;
208		return IIO_VAL_INT_PLUS_MICRO;
209	default:
210		return -EINVAL;
211	}
212}
213
214static int hdc2010_write_raw(struct iio_dev *indio_dev,
215			     struct iio_chan_spec const *chan,
216			     int val, int val2, long mask)
217{
218	struct hdc2010_data *data = iio_priv(indio_dev);
219	int new, ret;
220
221	switch (mask) {
222	case IIO_CHAN_INFO_RAW:
223		if (chan->type != IIO_CURRENT || val2 != 0)
224			return -EINVAL;
225
226		switch (val) {
227		case 1:
228			new = HDC2010_HEATER_EN;
229			break;
230		case 0:
231			new = 0;
232			break;
233		default:
234			return -EINVAL;
235		}
236
237		mutex_lock(&data->lock);
238		ret = hdc2010_update_drdy_config(data, HDC2010_HEATER_EN, new);
239		mutex_unlock(&data->lock);
240		return ret;
241	default:
242		return -EINVAL;
243	}
244}
245
246static const struct iio_info hdc2010_info = {
247	.read_raw = hdc2010_read_raw,
248	.write_raw = hdc2010_write_raw,
249	.attrs = &hdc2010_attribute_group,
250};
251
252static int hdc2010_probe(struct i2c_client *client)
253{
254	struct iio_dev *indio_dev;
255	struct hdc2010_data *data;
256	u8 tmp;
257	int ret;
258
259	if (!i2c_check_functionality(client->adapter,
260	    I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
261		return -EOPNOTSUPP;
262
263	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
264	if (!indio_dev)
265		return -ENOMEM;
266
267	data = iio_priv(indio_dev);
268	i2c_set_clientdata(client, indio_dev);
269	data->client = client;
270	mutex_init(&data->lock);
271
272	/*
273	 * As DEVICE ID register does not differentiate between
274	 * HDC2010 and HDC2080, we have the name hardcoded
275	 */
276	indio_dev->name = "hdc2010";
277	indio_dev->modes = INDIO_DIRECT_MODE;
278	indio_dev->info = &hdc2010_info;
279
280	indio_dev->channels = hdc2010_channels;
281	indio_dev->num_channels = ARRAY_SIZE(hdc2010_channels);
282
283	/* Enable Automatic Measurement Mode at 5Hz */
284	ret = hdc2010_update_drdy_config(data, HDC2010_AMM, HDC2010_AMM);
285	if (ret)
286		return ret;
287
288	/*
289	 * We enable both temp and humidity measurement.
290	 * However the measurement won't start even in AMM until triggered.
291	 */
292	tmp = (data->measurement_config & ~HDC2010_MEAS_CONF) |
293		HDC2010_MEAS_TRIG;
294
295	ret = i2c_smbus_write_byte_data(client, HDC2010_REG_MEASUREMENT_CONF, tmp);
296	if (ret) {
297		dev_warn(&client->dev, "Unable to set up measurement\n");
298		if (hdc2010_update_drdy_config(data, HDC2010_AMM, 0))
299			dev_warn(&client->dev, "Unable to restore default AMM\n");
300		return ret;
301	}
302
303	data->measurement_config = tmp;
304
305	return iio_device_register(indio_dev);
306}
307
308static void hdc2010_remove(struct i2c_client *client)
309{
310	struct iio_dev *indio_dev = i2c_get_clientdata(client);
311	struct hdc2010_data *data = iio_priv(indio_dev);
312
313	iio_device_unregister(indio_dev);
314
315	/* Disable Automatic Measurement Mode */
316	if (hdc2010_update_drdy_config(data, HDC2010_AMM, 0))
317		dev_warn(&client->dev, "Unable to restore default AMM\n");
318}
319
320static const struct i2c_device_id hdc2010_id[] = {
321	{ "hdc2010" },
322	{ "hdc2080" },
323	{ }
324};
325MODULE_DEVICE_TABLE(i2c, hdc2010_id);
326
327static const struct of_device_id hdc2010_dt_ids[] = {
328	{ .compatible = "ti,hdc2010" },
329	{ .compatible = "ti,hdc2080" },
330	{ }
331};
332MODULE_DEVICE_TABLE(of, hdc2010_dt_ids);
333
334static struct i2c_driver hdc2010_driver = {
335	.driver = {
336		.name	= "hdc2010",
337		.of_match_table = hdc2010_dt_ids,
338	},
339	.probe = hdc2010_probe,
340	.remove = hdc2010_remove,
341	.id_table = hdc2010_id,
342};
343module_i2c_driver(hdc2010_driver);
344
345MODULE_AUTHOR("Eugene Zaikonnikov <ez@norphonic.com>");
346MODULE_DESCRIPTION("TI HDC2010 humidity and temperature sensor driver");
347MODULE_LICENSE("GPL");